Urinary incontinence is a significant health concern worldwide. Millions of people worldwide suffer from this problem. There are many different forms of incontinence. One of the most common is known as stress urinary incontinence (hereafter SUI).
A pubovaginal sling procedure is a surgical method involving the placement of a sling to stabilize or support the bladder neck or urethra. There are a variety of different sling procedures. Descriptions of different sling procedures are disclosed in U.S. Pat. Nos. 5,112,344; 5,611,515; 5,842,478; 5,860,425; 5,899,909; 6,039,686; 6,042,534 and 6,110,101.
Slings for treating incontinence may be constructed from synthetic materials such as polypropylene, polytetrafluoroethylene, polyester and silicone. Slings constructed from non-synthetic materials include allografts, homografts, heterografts, autologous tissues, cadaveric fascia and fascia lata. The strength and other properties of certain non-synthetic sling materials have been reported in the literature. See, Chaikin et al., Weakened Cadaveric Fascial Sling: An Unexpected Cause of Failure, Journal of Urology, Vol. 160, 2151 (December 1998); Choe et al., Autologous, Cadaveric, and Synthetic Materials Used in Sling Surgery: Comparative Biomechanical Analysis; Urology 58 (3), Pps. 482-86; 2001; and Lemer et al., Tissue Strength Analysis of Autologous and Cadaveric Allografts of the Pubovaginal Sling, Neurology and Urodynamics 18:497-503 (1999). While some non-synthetic sling materials are generally preferred by surgeons and patients, the quality of some non-synthetic materials (e.g. cadaveric sling material) varies greatly.
The supply of non-synthetic materials for slings varies greatly. Certain sizes of non-synthetic materials can be especially difficult to secure in a timely fashion. For example, autologous material may be difficult or impossible to harvest from some patients due to a variety of factors, including the health of the patient and the size of the tissue needed for a sling.
Some surgeons prefer synthetic materials, as they are readily available. The influence of various sling materials on tissue has been investigated. See Ulmsten et al., Intravaginal Slingplasty (IVS): An Ambulatory Surgical Procedure For Treatment of Female Urinary Incontinence, Scand. J. Urol. Nephrol 29: 75-82 (1995); Falconer et al., Influence of Different Sling Materials on Connective Tissue Metabolism in Stress Urinary Incontinent Women, Int. Urogynecol. J. (2001) (Suppl. 2): S19-S23; and Bent et al., Tissue Reaction to Expanded Polytetrafluoroethylene Suburethral Sling for Urinary Incontinence: Clinical and Histological Study, Am. J. Obstet. Gynecol., Vol 169, No. 5 Pps. 1198-1204 (1993).
Other relative advantages and disadvantages exist between non-synthetic and synthetic sling materials.
Some surgical procedures for incontinence utilize autologous tissue to provide a sling. See Aldridge, Transplantation of Fascia for Relief of Urinary Stress Incontinence, Am. J. of Obstetrics and Gynecology, v. 44, pages 398-411 (1948). There are significant recovery and morbidity issues associated with harvesting the sling material from the patient. See Sloane et al., Stress Incontinence of Urine: A Retrospective Study of the Complications and Late Results of Simple Suprapubic Suburethral Fascial Slings, J. of Urology, vol. 110, Pps. 533-536 (1973).
Some pubovaginal sling procedures extend a sling from the rectus fascia in the abdominal region, to a position below the urethra, and back again to the rectus fascia. Some slings are anchored in the abdominal fascia by virtue of suturing the sling material to the patient's abdominal tissue (e.g. rectus fascia). See Blaivas, Commentary: Pubovaginal Sling Procedure, Current Operative Urology, Edited by E. D. Whitehead, Philadelphia: J. B. Lippincott Co. Pp. 93-100 (1990) (biologic sling); and Moir, The Gauze-Hammock Operation, The Journal of Obstetrics and Gynaecology of the British Commonwealth, Vol. 75, No. 1, Pps. 1-9 (1968) (synthetic implant). Although serious complications associated with sling procedures are infrequent, they do occur. Complications include urethral obstruction, prolonged urinary retention, bladder perforations, damage to surrounding tissue, and sling erosion.
The Tension-free Vaginal Tape (TVT) procedure (available from Ethicon, of N.J.) utilizes a Prolene™ nonabsorbable, polypropylene mesh. The TVT mesh extends from the rectus fascia in the abdominal region, to a position below the urethra, and back again to the rectus fascia. No suture is recommended to tie the end of the mesh to the rectus fascia. Problems with the TVT procedure are documented in the literature and patents. See PCT publication nos. PCT WO 00/74613 and PCT WO 00/74594, U.S. Pat. Nos. 6,273,852; 6,406,423; and 6,478,727, and published U.S. Pat. Application Nos. 2002-0091373-A1, 2002-0107430-A1, 2002-0099258-A1 and US-2002-0099259-A1. See also, Walters, Mark D., Percutaneous Suburethral Slings: State of the Art, presented at the conference of the American Urogynecologic Society, Chicago (October 2001) and PCT International Publication No. WO 02/26108.
Additional sling procedures are disclosed in Published U.S. Pat. Appl. No. US 2001/0018549A1, and PCT Publication Nos. WO 02/39890 and WO 02/069781.
PCT Published Application No. WO 00/74633 discloses a tape for treating SUI. The tape is a combination of synthetic materials and a natural material centered between the synthetic materials. The natural material may be placed over or incorporated within a generally central portion of the synthetic material. The natural material may be connected to the synthetic material by sewing, a bio-compatible glue or cell culturing techniques.
Published U.S. Pat. Appl. No. 2002/0099260 discloses an implantable device or tape for use in correcting urinary incontinence. The tape includes sprayed polypropylene fibers that result in a strong implantable device. The tape also has a silicone-coated portion and tapered free ends.
U.S. Pat. No. 6,306,079 discloses a mesh pubovaginal sling comprising two pieces. One piece comprises a polypropylene mesh and a second mesh portion comprises an absorbable material such as poly-dioxanone. One piece may be inserted at the endopelvic fascia and the other in the suprapubic region. The two pieces are then connected via suture to support prolapsed organs so as to relieve urinary stress incontinence.
U.S. Pat. No. 6,355,065 discloses an implantable support that may be used in suburethral stabilization procedures for reducing stress incontinence. Ends of the support are folded to reinforce suture holes and to inhibit fraying or rupturing. Threading mechanisms may be provided to facilitate threading of sutures through suture holes. A removable, elongated clip may be placed on an intermediate portion of the implant to inhibit folding of the implant about its longitudinal axis. This document speculates that longitudinal folding of the implant could cause dead space in which bacteria could collect.
U.S. Pat. No. 6,042,534 discloses a stabilization sling for use in minimally invasive pelvic surgery. The sling may include reinforced suture receiving sites. Ends of the sling may be folded over to reinforce the sling.
PCT International Publication No. WO 02/28312 discloses a sub-urethral supporting assembly for treating female SUI. A junction part is disclosed for connecting two ends of a support tape.
Published U.S. Pat. Application No. 2002/0028980 discloses a Y-shaped implantable article for use in a sacral colpopexy procedure. Published U.S. Pat. Application No. 2002/0082619 discloses a reinforcing fastener guide for enhancing the functional longevity of an implant such as a sling.